There are many kinds of portable gas-measuring devices known that have to be carried by persons who spend time in regions, in which they may be exposed to harmful gases. Such portable gas-measuring devices have to be tested regularly for their operability, i.e., whether they react at all to the gas or gases to be detected by them. Besides, such a mere operating test, test gas with a known concentration may also be fed to the gas-measuring device in a so-called calibrating station in order to calibrate the measuring signal of the gas-measuring device.
This means calibrating stations for portable gas-measuring devices are used for testing and adjusting portable gas-measuring devices. The calibrating stations usually have a plurality of modules, so-called test modules, with device-specific mounts for gas-measuring devices. The gassing processes may be directly controlled by the test modules or via a central master module. Gases are fed to the portable gas-measuring devices for the tests and adjustments. Furthermore, the modules also have communication interfaces to exchange data with the portable gas-measuring devices.
Calibrating stations for gas-measuring devices, which need a test gas or calibrating gas and a purge gas, inert gas or zero gas for monitoring the operations and calibrating the gas-measuring devices, are known from the general state of the art.
Such modular-structured calibrating stations are already commercially available. Such a calibrating station for portable gas-measuring devices is known, for example, from the patent application US 2006/0156789 A1. In that case, a plurality of test modules may be coupled to one another in a gas-communicating manner, such that gases can be forwarded from one test module to an adjacent test module. The test modules are, so to say, connected in series, i.e., the portable gas-measuring devices in the respective test modules are correspondingly individually gassed and tested one after the other. This “internal” series connection of the test modules leads, however, to long test times for the portable gas-measuring devices and thus to high costs for the user. Furthermore, besides the connection between adjacent test modules in a gas-communicating manner, it must be ensured that these gas modules are also fixed to one another frictionally in order to be able to reliably maintain the gas-communicating connection permanently.